Cattle vaccination

Sir - When faced with an outbreak of foot and mouth disease it is emergency protective vaccination, close to the centres of disease, that is proposed, not year-on-year widespread prophylactic vaccination (Letters, August 13).

The process uses antigens free from non-structural proteins (NSP) of the foot and mouth disease virus. These vaccines confer immunity quickly. Even if an animal is already incubating foot and mouth, they greatly reduce the amount of virus the animal produces. This process enabled the Dutch to bring their 2001 outbreak under control in just eight days.

With NSP-free vaccines, a test can distinguish between flocks and herds that have responded solely to vaccination, and are thus free of disease, and those which have responded to infection and so need to be culled.

So robust is this approach that, in 2002, the Office International des Epizooties (OIE), which oversees international disease-free status, changed the International Animal Health Code to allow countries to return to disease-free status six months after vaccination, as opposed to 12 months.

In September 2003, the EU endorsed this approach. The EU also allowed member states to treat vaccinated meat and milk (destined for the home market) no differently from their nonvaccinated equivalents.

As most animals can then live out their economic lives, costs of vaccination are far less than the cost of slaughter, compensation and disposal.

It was welcome news that in the recent outbreak the Government secured 300,000 doses of emergency vaccine and put vaccination teams on standby.